Abstract

Due to the rapid growth of the composite market, several European laws have emerged to minimize their environmental impact (EU 2000/53 / EC, End of life vehicles), as well as to make rational use of landfills (EU 1999/31 / EC). For example, in the aeronautical sector, composites can reach 50% by weight of the aircraft. Consequently, recyclability is a key issue. The objective of this work is the study of the recycling techniques of carbon fiber composites with thermoset polymer matrix in order to obtain fibers with similar properties to the original ones. In this way, the fibers could be reused in new composites by themselves or together with flass fibers in the manufacture of new hybrid composite materials. By this hybridization, materials with properties far superior to the GFRP would be obtained, but at much lower cost than the original CFRP. Therefore, this recycling and reprocesing strategies provides great economical attractiveness.  The main objective of the project is to study and optimize the recyclability of cured carbon fiber / epoxy prepregs for use in hybrid materials. Starting from a pyrolysis in a controlled atmosphere reactor, followed by a oxidation, carbon fibers with properties similar to virgin fibers are obtained, with a loss less than 20% of the tensile strength. An evaluation of the different parameters of the recycling process has been carried out in order to optimize the procedure. The characterization of the fibers includes tensile tests, scanning electron microscopy and Raman spectroscopy.

Abstract

In an attempt to cover the needs and requirements of consumers, packaging without good recyclability is sometimes introduced in the market. This is more evident in the case of polyethylene terephthalate (PET). PET is a highly recyclable material that results in a recycled product with enhanced quality. However, there are other type of PET multilayered packaging that are being introduced in the market. These packaging products include additional materials such as other type of polymers, metals, paper, etc., as well as different type of pigments, colouring agents and impurities confering a critical colour to the packaging. When this new packaging arrives to the recycler it generates problems, resulting in low quality products or even rejected, being deposited in landfill. This implies an important environmental reduction (mainly in the CO2 emissions) and in the economic affairs. For this reason, the recycling companies and, in general, waste management companies, are interested in alternatives that allow these residues to have a viable outlet. This development is presented as a solution to the problem of these particular PET multilayered residues. The main objective is the industrial development of thermosetting resins (alkyds and unsaturated polyesters) that include in their composition materials obtained from the chemical recycling of these multilayered packaging, at an affordable price and with reduced environmental impact.